Compressor

ABSTRACT

A compressor includes: a cylinder main body; a valve block; a cylinder head; a first seal group composed of a plurality of seal parts; and a second seal group composed of a plurality of seal parts. The valve block includes a guide-out flow passage which opens between the seal parts composing the first seal group and opens between the seal parts composing the second seal group. The guide-out flow passage is linked to an outer pipe for conveying a leaked gas from a compression chamber to a predetermined place.

FIELD OF THE INVENTION

The present invention relates to a compressor for compressing a gas.

BACKGROUND ART

Compressors of reciprocating types have been conventionally known to each compress a gas introduced into a compression chamber formed in a cylinder by reciprocating a piston in the cylinder. As shown in FIG. 7, a compressor 100 of a reciprocating type disclosed in Japanese Unexamined Patent Publication No. SHO 62-17381 includes: a cylindrical seal holder 102 arranged on a drive part 101; a cylindrical cylinder block 103 provided with a piston 105 therein, having an intake port 106, and connected to the seal holder 102; and a cylinder head 104 having a discharge port 107 and connected to the cylinder block 103. Seal parts 108 are provided respectively between the seal holder 102 and the cylinder block 103, and between the cylinder block 103 and the cylinder head 104. Each of the seal parts 108 prevents the gas from leaking out from the compression chamber 109 to an outside.

For instance, as disclosed in Japanese Unexamined Patent Publication No. SHO 62-17381, the seal part 108 seals a gap between the members defining the compression chamber 109. However, a compressor for providing a combustible gas having a higher pressure, even provided with a seal part, has a possibility that the combustible gas compressed in a compression chamber to have the higher pressure may leak out to an unintended place on an outside of the compressor.

SUMMARY OF THE INVENTION

An object of the present invention is to prevent a gas which may happen to leak out between members defining a compression chamber to further leak out to an unintended place on an outside of the compressor.

A compressor according to the present invention is a compressor of a reciprocating type for compressing a combustible gas, the compressor including: a piston; a cylinder main body which receives the piston inserted therein; a valve block fixedly attached to the cylinder main body at a portion thereof closer to a leading end of the piston and formed with a through hole; a cylinder head fixedly attached to the valve block at a portion thereof opposite to the cylinder main body and including an insertion part to be inserted in the through hole; a first seal group composed of a plurality of seal parts arranged between the valve block and the cylinder main body; and a second seal group composed of a plurality of seal parts arranged between the valve block and the insertion part of the cylinder head, wherein the piston, the cylinder main body, the insertion part, and the valve block define a compression chamber thereamong. The valve block has a guide-out flow passage which opens between the seal parts composing the first seal group arranged between the valve block and the cylinder main body, and opens between the seal parts composing the second seal group arranged between the valve block and the insertion part. The guide-out flow passage is linked to a pipe for conveying a leaked gas to a predetermined place.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 schematically illustrates a configuration of a hydrogen station in an embodiment.

FIG. 2 schematically illustrates a part of a configuration of a compressor according to the embodiment.

FIG. 3 is an enlarged view of a portion A shown in FIG. 2. Each of FIG. 4A and FIG. 4B shows a modification of a guide-out flow passage of the compressor according to the embodiment.

Each of FIG. 5A and FIG. 5B shows a modification of a first widen part of the compressor according to the embodiment.

Each of FIG. 6A and FIG. 6B shows a modification of a second widen part of the compressor according to the embodiment.

FIG. 7 shows a conventional compressor.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Directional terms, such as “up”, “down”, “right” and the like, used hereinafter in the text merely aim at clarifying description about the embodiment, and thus should not be limitedly construed.

As illustrated in FIG. 1, a compressor 10 according to the embodiment is provided in a hydrogen station 1. The hydrogen station 1 is a facility including a compressor unit 2, a pressure accumulator 3, and a dispenser 4 to compress a hydrogen gas which is an exemplary combustible gas to have a superhigh pressure and supplying the compressed hydrogen gas to a destination, such as a fuel cell vehicle 5. The compressor unit 2 includes the compressor 10 for compressing the hydrogen gas to have the high pressure and a housing 9 for accommodating the compressor 10. The housing 9 is provided with an explosion proof ventilating fan 11 inside the housing 9 for dispersing the hydrogen gas having leaked out from the compressor 10 to an outside of the housing 9. The pressure accumulator 3 is a container for accumulating the hydrogen gas having the high pressure and supplied from the compressor unit 2 in the high-pressure state. The dispenser 4 is a device for providing the fuel cell vehicle 5 with the hydrogen gas supplied from the pressure accumulator 3 and having the high pressure while adjusting the pressure and a flow rate of the gas.

As shown in FIG. 2, the compressor 10 is a compressor of a reciprocating type, the compressor 10 including a cylinder 12, a piston 13, and an unillustrated piston rod. The cylinder 12 is arranged on an unillustrated drive mechanism for driving the piston 13. The cylinder 12 is formed with a columnar space inside. The piston 13 is slidable in an up-down direction in the space inside the cylinder 12 and connected to the drive mechanism via the piston rod.

The cylinder 12 includes: a cylinder main body 20 arranged above the drive mechanism; a valve block 21 arranged on the cylinder main body 20; and a cylinder head 22 arranged on the valve block 21.

The cylinder main body 20 has a cylindrical shape which is long in one direction (the up-down direction in the drawing), and is formed with a main body inner space 20 a having a columnar shape and extending in the one direction at an inner center thereof. The main body inner space 20 a vertically penetrates the cylinder main body 20 and opens to an upper end surface 20 b of the cylinder main body 20.

The valve block 21 is arranged on the cylinder main body 20 and formed with a block inner space 21 a having a columnar shape and extending in the one direction at an inner center of the valve block 21. The block inner space 21 a has a circular shape having the same diameter as the diameter of the main body inner space 20 a in a top view, and vertically penetrates the valve block 21. The block inner space 21 a opens to an upper surface and a lower surface of the valve block 21. The block inner space 21 a communicates with the main body inner space 20 a and is defined by a center inner circumferential surface 21 which is an annular circumferential surface extending in the up-down direction.

The cylinder head 22 is arranged on the valve block 21. The cylinder head 22 has a head main body 22 a and an insertion part 22 b protruding downward from a lower surface of the head main body 22 a.

The lower surface of the valve block 21 is formed with a lower-surface recess 21 b for receiving an upper end of the cylinder main body 20 to fit therein. The lower-surface recess 21 b has a circular cross-section in a bottom view. The lower-surface recess 21 b is defined by a lower inner circumferential surface 21 e which is an annular circumferential surface extending in the up-down direction and by a downward surface 21 f connecting an upper end of the lower inner circumferential surface 21 e and a lower end of a center inner circumferential surface 21 d defining the block inner space 21 a with each other.

The upper surface of the valve block 21 is formed with an upper-surface recess 21 c for receiving the insertion part 22 b to fit therein. The upper-surface recess 21 c has a circular cross-section in a top view. The upper-surface recess 21 c is defined by an upper inner circumferential surface 21 g and an upward surface 21 h, the upper inner circumferential surface 21 g being an annular circumferential surface extending in the up-down direction, and the upward surface 21 h connecting an upper end of the center inner circumferential surface 21 d defining the block inner space 21 a and a lower end of the upper inner circumferential surface 21 g with each other.

The valve block 21 is connected to the cylinder main body 20 in a state where the downward surface 21 f is in contact with the upper end surface 20 b of the cylinder main body 20 and the lower inner circumferential surface 21 e is in contact with an outer circumferential surface 20 c of the cylinder main body 20. In other words, the downward surface 21 f of the valve block 21 and the upper end surface 20 b of the cylinder main body 20 are in contact with each other, and the lower inner circumferential surface 21 e of the valve block 21 and the outer circumferential surface 20 c of the cylinder main body 20 are in contact with each other.

A contact region C1 between the valve block 21 and the cylinder main body 20 is provided with a first seal group 31 composed of a plurality of seal parts. Each of the seal parts composing the first seal group 31 fits in an annular groove formed on the upper end surface 20 b or the outer circumferential surface 20 c for sealing the contact region C1.

The upper end surface 20 b and the outer circumferential surface 20 c of the cylinder main body 20 define a corner 20 e therebetween where a first widen part 35 for forming a gap between the cylinder main body 20 and the valve block 21 is defined. The first widen part 35 is an annular space defined by the corner 20 e subjected to chamfering so as to extend in a circumferential direction of the cylinder main body 20. The first widen part 35 is located between the seal parts of the first seal group 31. That is to say, each of the upper end surface 20 b of the cylinder main body 20 and the outer circumferential surface 20 c of the cylinder main body 20 is formed with at least one seal part, and thus the first widen part 35 is located between the seal parts.

The valve block 21 has a top surface 21 i facing upward and a bottom surface 21 j facing downward. The top surface 21 i connects an upper end of the upper inner circumferential surface 21 g and an upper end of an outer circumferential surface 21 k of the valve block 21 with each other. The bottom surface 21 j connects a lower end of the lower inner circumferential surface 21 e and a lower end of the outer circumferential surface 21 k of the valve block 21 with each other.

The valve block 21 is connected to the cylinder head 22 in a state where the upward surface 21 h is in contact with a leading end surface 22 c facing downward in the insertion part 22 b and the upper inner circumferential surface 21 g is in contact with an outer circumferential surface 22 d in the insertion part 22 b. In other words, the upward surface 21 h of the valve block 21 and the leading end surface 22 c of the insertion part 22 b are in contact with each other, and the upper inner circumferential surface 21 g of the valve block 21 and the outer circumferential surface 22 d of the insertion part 22 b are in contact with each other.

A contact region C2 between the valve block 21 and the cylinder head 22 is provided with a second seal group 32 composed of a plurality of seal parts. Each of the seal parts composing the second seal group 32 fits in an annular groove formed on the outer circumferential surface 22 d of the insertion part 22 b for sealing the contact region C2.

The upper inner circumferential surface 21 g of the valve block 21 defines a second widen part 36 for forming a gap between the valve block 21 and the cylinder head 22. The second widen part 36 is an annular space defined by the upper inner circumferential surface 21 g subjected to grooving so as to extend in a circumferential direction of the upper inner circumferential surface 21 g. The second widen part 36 is located between the seal parts composing the second seal group 32.

Each of the seal parts composing the first seal group 31 and the seal parts composing the second seal group 32 has an O ring 33 and a backup ring 34 (see FIG. 3). The O ring 33 is an annular member configured to hinder the gas from leaking out from the contact region C1, C2 to the outside. The backup ring 34 is an annular member disposed adjacent to the O ring 33 and configured to suppress deformation of the O ring 33 which receives a load with a large pressure difference. The backup ring 34 disposed in this manner can more effectively reduce the leakage of the gas.

The cylinder 12 is formed with a compression chamber 12S inside as defined by an inner circumferential surface 20 d of the cylinder main body 20 defining the main body inner space 20 a, the center inner circumferential surface 21 d of the valve block 21, the leading end surface 22 c of the cylinder head 22, and a leading end surface 13a of the piston 13. The valve block 21 holds an unillustrated intake valve for taking the hydrogen gas from the outside into the compression chamber 12S and an unillustrated discharge valve for discharging the hydrogen gas from the compression chamber 12S to the outside.

An unillustrated adapter member extending in a columnar shape from a leading end of the insertion part 22 b to the compression chamber 12S may be attached to the insertion part 22 b of the cylinder head 22. The volume of the compression chamber 12S is changeable by attachment and detachment of the adapter member to and from the insertion part 22 b. Consequently, the compressibility of the compressor 10 is adjustable.

The valve block 21 has a guide-out flow passage 40 for guiding the hydrogen gas having leaked out from the compression chamber 12S to an outside of the valve block 21. The guide-out flow passage 40 is formed in the valve block 21 and includes a first flow passage 41, a second flow passage 42, and a connection flow passage 43.

The first flow passage 41 has an inner end opening to the first widen part 35 and extends in one direction (a right direction in FIG. 2) from the contact region C1 (or the first widen part 35).

The second flow passage 42 has an inner end opening to the second widen part 36, and extends in the one direction from the contact region C2 (or the second widen part 36).

The connection flow passage 43 has an intermediate section 44 connecting the first flow passage 41 and the second flow passage 42 with each other, and a merging section 45 connected to the intermediate section 44.

The intermediate section 44 extends in a direction (upward in FIG. 2) perpendicular to the one direction, and connects an outer end of the first flow passage 41 and an outer end of the second flow passage 42 with each other. The intermediate section 44 has an inner diameter larger than an inner diameter of the first flow passage 41 and an inner diameter of the second flow passage 42. However, the inner diameter of the intermediate section 44 is not limited thereto, and may be the same as the inner diameter of each of the first flow passage 41 and the second flow passage 42. The intermediate section 44 is made by, for example, forming a passage extending from the bottom surface 21 j of the valve block 21 to the outer end of the second flow passage 42, and thereafter closing a section of the passage from the bottom surface 21 j to the outer end of the first flow passage 41 with a closing member 49.

The merging section 45 has an inner end connected to the intermediate section 44. For instance, in the example shown in FIG. 2, the inner end of the merging section 45 is connected to a junction C3 between the second flow passage 42 and the intermediate section 44, that is, connected to an end of the intermediate section 44. The merging section 45 extends from the inner end thereof in a direction (the right direction in FIG. 2) perpendicular to the intermediate section 44. Therefore, the merging section 45 allows a leaked gas flowing out from the first flow passage 41 via the intermediate section 44 and a leaked gas flowing out from the second flow passage 42 to merge therein and the merged gas to flow therethrough.

The merging section 45 has an outer end linked to an upstream end of the outer pipe 47 on the outer circumferential surface 21 k of the valve block 21. The outer pipe 47 is arranged on the outside of the valve block 21. The merging section 45 has an inner diameter larger than the inner diameter of the first flow passage 41 and the inner diameter of the second flow passage 42.

The outer pipe 47 has a downstream end opening to a vicinity of the explosion proof ventilating fan 11 (FIG. 1) provided on the housing 9 of the compressor unit 2. The outer pipe 47 may be linked to the explosion proof ventilating fan 11. The explosion proof ventilating fan 11 is configured to disperse the hydrogen gas in the housing 9 to the atmosphere on the outside of the housing 9.

In an operation of the compressor 10, compression and expansion are repeated in the compression chamber 12S in accordance with a sliding movement of the piston 13, and the hydrogen gas compressed to have the high pressure is discharged from the compression chamber 12S. The contact region C1 and the contact region C2 are sealed with the seal parts of the first seal group 31 and the seal parts of the second seal group 32 respectively to suppress leakage of the hydrogen gas from the compression chamber 12S to the outside of the compressor 10. However, in the operation of the compressor 10, there is a possibility that only a part of the hydrogen gas compressed to have the high pressure may leak out to the contact region C1 and the contact region C2.

In such a case where the hydrogen gas leaks out to the contact region C1 and the contact region C2, first, a seal part located closer to the compression chamber 12S suppress further leakage of the hydrogen gas. Should the hydrogen gas leak out through the seal part located closer to the compression chamber 12S, then, the seal part located away from the compression chamber 12S suppress still further leakage. At this time, the hydrogen gas having leaked between the seal parts of the first seal group 31 or between the seal parts of the second seal group 32 is guided to the first flow passage 41 of the guide-out flow passage 40 via the first widen part 35 or to the second flow passage 42 of the guide-out flow passage 40 via the second widen part 36.

Each of the first widen part 35 and the second widen part 36 is an annular space extending in the circumferential direction of each of the cylinder main body 20 and the valve block 21. Accordingly, even the hydrogen gas having leaked out at a position in the circumferential direction other than the position to which the guide-out flow passage 40 opens is allowed to advance and reach the guide-out flow passage 40 via the first widen part 35 and the second widen part 36. As a result, it is possible to effectively guide the leaked gas to the guide-out flow passage 40.

The hydrogen gas in the first flow passage 41 and the hydrogen gas in the second flow passage 42 merge in the connection flow passage 43 and the merged gas is conveyed out to the vicinity of the explosion proof ventilating fan 11 (predetermined place) via the outer pipe 47 and dispersed to the atmosphere on the outside of the compressor unit 2. This consequently suppresses leakage of the gas from the contact region C1 between the cylinder main body 20 and the valve block 21 and from the contact region C2 between the valve block 21 and the cylinder head 22 to an unintended place on the outside of the compressor 10.

The provided connection flow passage 43 allows the hydrogen gas having flowed out from the first flow passage 41 and the gas having flowed out from the second flow passage 42 to merge therein and serves as a single flow passage for guiding out the merged gas to the outer pipe 47. This reduces a risk of gas leakage which may occur in relation to the outer pipe 47 linked to the valve block 21.

The inner diameter of the merging section 45 is larger than the inner diameter of the first flow passage 41 and the inner diameter of the second flow passage 42, but is not limited thereto, and may be the same as the inner diameter of each of the first and second flow passages. In a case where the inner diameter of the merging section 45 is smaller, there is a risk that a pressure loss occurs in the merging section 45 at the merging of the gas from the first flow passage 41 and the gas from the second flow passage 42 therein, and the pressure increases at upstream ends of the first flow passage 41 and the second flow passage 42. The inner diameter of the merging section 45 set larger in consideration of the risk succeeds in suppressing the pressure loss in the merging section 45 and effectively guiding out the leaked gas to the outer pipe 47.

The above-described embodiment merely shows examples in all the aspects, and thus should not be considered to be limited. The scope of the invention should be defined by the scope of claims, not the description of the above-described embodiments, and further cover meanings equivalent to those readable in the scope of claims and all the changes falling within the scope of the claims. Accordingly, the present invention covers the following embodiments as well.

Although the outer pipe 47 is linked to the vicinity of the explosion proof ventilating fan 11 in the embodiment, the linkage is not limited thereto. For instance, the outer pipe 47 may be linked to a pipe connected to the outside of the compressor 10 for discharging the leaked gas, or may be linked to an intake pipe for taking the gas into the compression chamber 12S.

Although the cylinder main body 20 of the cylinder 12 has the first widen part 35 in the embodiment, the cylinder 12 may exclude the first widen part 35. In this case, the first flow passage 41 opens at the lower inner circumferential surface 21 e of the valve block 21.

Although the valve block 21 of the cylinder 12 has the second widen part 36 in the embodiment, the cylinder 12 may exclude the second widen part 36. In this case, the second flow passage 42 opens at the upper inner circumferential surface 21 g of the valve block 21.

Although each of the seal parts composing the first seal group 31 and the seal parts composing the second seal group 32 has the O ring 33 and the backup ring 34, the configuration of the seal part is not limited thereto. For instance, each of the seal parts may have only the 0 ring 33.

Although the merging section 45 of the connection flow passage 43 extends straightly from the second flow passage 42 in the embodiment, the extension manner is not limited thereto. For example, the merging section 45 may extend straightly from the first flow passage 41, or may extend from a position deviating from the first flow passage 41 and the second flow passage 42 as shown in FIG. 4A. In this case, the merging section 45 is connected to the intermediate section 44 between the outer end of the first flow passage 41 and the outer end of the second flow passage 42.

Although the guide-out flow passage 40 includes the connection flow passage 43 in the embodiment, the guide-out flow passage 40 may exclude the connection flow passage 43. In this case, as shown in FIG. 4B, the guide-out flow passage 40 serves as each of the first flow passage 41 and the second flow passage 42 independently, and thus the first flow passage 41 and the second flow passage 42 are independently connected to the outer pipe 47 on the outer circumferential surface 21 k of the valve block 21 without joining each other.

Although the first widen part 35 is defined by the corner 20 e of the cylinder main body 20 subjected to the chamfering, the definition is not limited thereto. For instance, the first widen part 35 may be defined as an annular groove formed on the lower inner circumferential surface 21 e of the valve block 21 as shown in FIG. 5A, or may be defined as an annular groove formed on the outer circumferential surface 20 c of the cylinder main body 20 as shown in FIG. 5B. The first widen part 35 may not necessarily extend entirely in the circumferential direction. This is applicable to the second widen part 36 as well.

Although the second widen part 36 is defined as an annular groove formed on the upper inner circumferential surface 21 g of the valve block 21, the definition is not limited thereto. For instance, the second widen part 36 may be formed of an annular space defined by an outer corner of the leading end surface 22 c of the insertion part 22 b of the cylinder head 22 subjected to the chamfering as shown in FIG. 6A, or may be defined as an annular groove formed on the outer circumferential surface 22 d of the insertion part 22 b of the cylinder head 22 as shown in FIG. 6B.

Hereinafter, the embodiment will be summarized

(1) A compressor according to the embodiment is a compressor of a reciprocating type for compressing a combustible gas, the compressor including: a piston; a cylinder main body which receives the piston inserted therein; a valve block fixedly attached to the cylinder main body at a portion thereof closer to a leading end of the piston and formed with a through hole; a cylinder head fixedly attached to the valve block at a portion thereof opposite to the cylinder main body and including an insertion part to be inserted in the through hole; a first seal group composed of a plurality of seal parts arranged between the valve block and the cylinder main body; and a second seal group composed of a plurality of seal parts arranged between the valve block and the insertion part of the cylinder head, wherein the piston, the cylinder main body, the insertion part, and the valve block define a compression chamber thereamong. The valve block has a guide-out flow passage which opens between the seal parts composing the first seal group arranged between the valve block and the cylinder main body, and opens between the seal parts composing the second seal group arranged between the valve block and the insertion part. The guide-out flow passage is linked to a pipe for conveying a leaked gas to a predetermined place.

In the embodiment, the region between the valve block and the cylinder main body is sealed by the first seal group composed of the plurality of seal parts. The region between the valve block and the insertion part of the cylinder head is sealed by the second seal group composed of the plurality of seal parts. Should the gas leak out between the seal parts of the first seal group or between the seal parts of the second seal group, the seal part located away from the compression chamber suppresses further leakage of the gas to the outside of the compressor. Furthermore, the guide-out flow passage which opens between the seal parts of the first seal group and between the seal parts of the second seal group guides out the leaked gas to the pipe for conveying the leaked gas to the predetermined place. This configuration suppresses the leakage of the gas to an unintended place through the first seal group and the second seal group. For instance, the predetermined place corresponds to a vicinity of an explosion-proof ventilating fan provided on a housing for accommodating the compressor, a pipe for discharging the leaked gas connected to the outside of the compressor, and an intake pipe for taking the gas into the compression chamber.

(2) The guide-out flow passage may include: a first flow passage extending in one direction from a region between the valve block and the cylinder main body; a second flow passage extending in the one direction from a region between the valve block and the insertion part; and a connection flow passage connecting the first flow passage and the second flow passage with each other and linked to the pipe.

In this aspect, the guide-out flow passage includes the first flow passage for allowing the gas having leaked out from the first seal group to flow therethrough, the second flow passage for allowing the gas having leaked out from the second seal group to flow therethrough, and the connection flow passage connecting the first flow passage and the second flow passage with each other. In other words, the first flow passage and the second flow passages join at the connection flow passage to form a single flow passage. This configuration allows the leaked gas to flow out from the single flow passage to the outside of the valve block, and thus can decrease the number of pipes required to be connected to the valve block. This consequently reduces a risk of gas leakage occurrence in relation to the pipes connected to the valve block.

(3) The connection flow passage may have a section allowing a leaked gas from the first flow passage and a leaked gas from the second flow passage to marge therein and the merged gas to flow therethrough, the section having an inner diameter larger than an inner diameter of each of the first flow passage and the second flow passage.

In this aspect, the inner diameter of the section of the connection flow passage allowing the leaked gas from the first flow passage and the leaked gas from the second flow passage to marge therein and the merged gas to flow therethrough is larger than the inner diameter of the first flow passage and the inner diameter of the second flow passage. The connection flow passage configured in this manner can effectively guide out the leaked gas to the outside.

(4) A first widen part may be defined between the valve block and the cylinder main body so as to extend in a circumferential direction and form a gap between the valve block and the cylinder main body. In this case, the guide-out flow passage may open to the first widen part.

In this aspect, the first widen part provided so as to extend in the circumferential direction permits even the gas having leaked out at a position other than the guide-out flow passage in the circumferential direction to advance and reach the guide-out flow passage via the first widen part. As a result, it is possible to effectively guide the leaked gas to the guide-out flow passage.

(5) A second widen part may be defined between the valve block and the insertion part of the cylinder head so as to extend in the circumferential direction and form a gap between the valve block and the insertion part. In this case, the guide-out flow passage may open to the second widen part.

In this aspect, the second widen part provided so as to extend in the circumferential direction permits even the gas having leaked out at a position other than the guide-out flow passage in the circumferential direction to advance and reach the guide-out flow passage via the second widen part. As a result, it is possible to effectively guide the leaked gas to the guide-out flow passage.

(6) At least one of a seal part located closer to the compression chamber than a position where the guide-out flow passage opens among the seal parts composing the first seal group and a seal part located closer to the compression chamber than another position where the guide-out flow passage opens among the seal parts composing the second seal group may have a sealing member and a backup ring disposed adjacent to the sealing member.

In this aspect, the seal part located closer to the compression chamber than the position where the guide-out flow passage opens has the sealing member and the backup ring disposed adjacent to the sealing member. This can further increase the sealing performance of the seal part.

As described heretofore, it is possible to prevent the gas having leaked out through the gap between the members defining the compression chamber from further leaking out to an unintended place on the outside of the compressor.

This application is based on Japanese Patent Application No. 2020-191802 filed on Nov. 18, 2020, the contents of which are hereby incorporated by reference.

Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention hereinafter defined, they should be construed as being included therein. 

1. A compressor of a reciprocating type for compressing a combustible gas, the compressor comprising: a piston; a cylinder main body which receives the piston inserted therein; a valve block fixedly attached to the cylinder main body at a portion thereof closer to a leading end of the piston and formed with a through hole; a cylinder head fixedly attached to the valve block at a portion thereof opposite to the cylinder main body and including an insertion part to be inserted in the through hole; a first seal group composed of a plurality of seal parts arranged between the valve block and the cylinder main body; and a second seal group composed of a plurality of seal parts arranged between the valve block and the insertion part of the cylinder head, wherein the piston, the cylinder main body, the insertion part, and the valve block define a compression chamber thereamong, and the valve block has a guide-out flow passage which opens between the seal parts composing the first seal group arranged between the valve block and the cylinder main body, and opens between the seal parts composing the second seal group arranged between the valve block and the insertion part, the guide-out flow passage being linked to a pipe for conveying a leaked gas to a predetermined place.
 2. The compressor according to claim 1, wherein the guide-out flow passage includes: a first flow passage extending in one direction from a region between the valve block and the cylinder main body; a second flow passage extending in the one direction from a region between the valve block and the insertion part of the cylinder head; and a connection flow passage connecting the first flow passage and the second flow passage with each other and linked to the pipe.
 3. The compressor according to claim 2, wherein the connection flow passage has a section allowing a leaked gas from the first flow passage and a leaked gas from the second flow passage to marge therein and the merged gas to flow therethrough, the section having an inner diameter larger than an inner diameter of each of the first flow passage and the second flow passage.
 4. The compressor according to claim 1, wherein a first widen part is defined between the valve block and the cylinder main body so as to extend in a circumferential direction and form a gap between the valve block and the cylinder main body, and the guide-out flow passage opens to the first widen part.
 5. The compressor according to claim 1, wherein a second widen part is defined between the valve block and the insertion part of the cylinder head so as to extend in a circumferential direction and form a gap between the valve block and the insertion part, and the guide-out flow passage opens to the second widen part.
 6. The compressor according to claim 1, wherein at least one of a seal part located closer to the compression chamber than a position where the guide-out flow passage opens among the seal parts composing the first seal group and a seal part located closer to the compression chamber than another position where the guide-out flow passage opens among the seal parts composing the second seal group has a sealing member and a backup ring disposed adjacent to the sealing member. 